A Tasmanian politician has urged her colleagues to end the "suffering and pain" of terminally ill people being driven to "desperate suicide", as the latest bid to change the laws to allow voluntary assisted dying is debated in Parliament.

Ms Giddings' speech in the Tasmanian House of Assembly kicked off the debate over the Voluntary Assisted Dying bill co-sponsored by Ms Giddings and Greens leader Cassy O'Connor, which would allow people to voluntarily end their lives using a lethal drug.

"The fact is that these patients are suffering intolerable pain that cannot be relieved, and their families are being left with the stressful memories of their loved one's dying experience," Ms Giddings said.

"Yet the law as it is gives them no choice to end their suffering and pain.

"This bill is about the patients, and there are hundreds of stories of people taking their own life because they could not bear the pain and suffering anymore."

Under the bill, to qualify to gain access to the drug you must be a Tasmanian adult who is judged competent to make the decision and have an eligible medical condition.

Access would also require diagnosis by a specialist and must be signed off by two independent doctors.

People 'want a choice'

Ms Giddings referenced evidence from the coroner's office in Victoria given as part of a parliamentary inquiry.

"How dare they presume to know what it's like to be in a position where you've been diagnosed with an incurable, chronically painful condition, where your suffering cannot be relived by palliation," Ms O'Connor told the crowd.

"Who is the church to tell us what we can do with our bodies at the end of our days?

"Who are these people who oppose this reform, to make that judgment on anyone's behalf?"

Liberal minister 'guarantees' there will be tragedies

Health Minister Michael Ferguson told Parliament he doubted it was possible to come up with a failsafe law.

"The reality is manslaughter, suicide and murder," he told Parliament.

Mr Ferguson said he had concerns about the welfare of vulnerable people.

"It's fairly obvious that in this elite debate they are at massive risk ... I guarantee it, they will be the new tragedies."

Labor leader Rebecca White said people were "the owners of their own bodies" and the bill was about providing choice.

"We must do better to alleviate the suffering and provide dignity and peace to people in their final stages of life," she told the debate.

"Individuals are the owners of their own bodies and should be allowed to make decisions about their own death.

"The conditions set out in this bill for eligibility to access an assisted death are robust and they do protect against misuse."

The campaign to legalise voluntary euthanasia began in the 1990s, after Tasmanian supporters formed the advocacy group Dying with Dignity in 1992, with the first bid to introduce voluntary euthanasia legislation rejected by the Tasmanian Parliament a few years later.